body {
    height: 100vh;
    background: url(../images/gou.jpg) no-repeat center;
    background-size: cover;
}

.header-in {
    height: 80px;
    line-height: 80px;
    text-align: center;
    font-size: 22px;
    font-weight: 500;
    color: #fb7299;
}

.control-in {
    /* background-color: aqua; */
    text-align: center;
}

.control button {
    background-color: #fb7299;
    color: #fff;
    text-align: center;
    font-size: 16px;
    cursor: pointer;
    transition: background-color .3s;
    padding: 8px 20px;
    border-radius: 2px;

}

.control button:hover {
    background-color: #ed8ca8;
}

.stu-in {
    /* background-color: #ed8ca8; */
    /* height: 400px; */

}

.group h3 {
    height: 40px;
    line-height: 40px;
    text-align: center;
}

.group h3 a {
    font-size: 14px;
    color: #3288dd;
    transition: all .3s;
}

.group h3 a:hover {
    font-weight: bold;
    color: #084f96;
    text-decoration: underline;
}

.group ul {
    display: flex;
    justify-content: center;
}


.group ul li {
    margin: 5px;
    width: 120px;
    height: 50px;
    line-height: 50px;
    box-sizing: content-box;
    border: 1px solid #f1f2f3;
    border-radius: 4px;
    background-color: #f6f7f8;
    color: #61666d;
    text-align: center;
    font-weight: 400;
    transition: background-color .3s, color .3s;
    position: relative;
}

.group ul li.active {
    background-color: #5ea6ee;
    color: #ffffff;
}


.close-btn {
    width: 15px;
    height: 15px;
    line-height: 15px;
    position: absolute;
    right: 0;
    top: 0;
    cursor: pointer;
    transition: all .3s;
}

.close-btn:hover {
    color: #ffff;
    background-color: #db3752;
    border-top-right-radius: 4px;
}


.group ul li.active {
    background-color: #438cd4;
    color: #fff;
}

.countdown {
    text-align: center;
    color: #d699aa;
    font-size: 18px;
    padding: 5px 0;
    font-weight: 500;
}

.control .btn-addGroup {
    background-color: #438cd4;
    margin: 10px 0;
}

.control .btn-addGroup:hover {
    background-color: #5ea6ee;
    margin: 10px 0;
}